Hello the last matomo comes with archive_tar 1.4.2, but this version fails with php 7.2
For example the download of the geoip2 data bases fails with:

PHP Fatal error: Cannot use result of built-in function in write context in /var/www/piwik/html/vendor/pear/archive_tar/Archive/Tar.php on line 662

This bug is also noted on the pear site